DPP4 and hepatocellular carcinoma: Dipeptidyl peptidase 4 enhances the biological activity of the CXCL10 secreted by HCC cells by inhibiting CD26, thus maintaining the chemotactic activity of the CXCR3-CXCL10 axis.175 Maintenance of that axis increases the trafficking rate of NK cells, which is beneficial for inhibiting HCC development.